“I believe it’s sheer obstinacy. You do not want to do these equations—simple equations too, mind you! Now then, about the stage-coaches. When did they meet, and in what time from starting? Now then—there are your figures, where did they meet? Look and tell me.”

Dexter took the half-sheet of paper, stared at it very doubtfully, and then looked up.

“Well!” said Mr Limpney. “Where did they meet?”

“Peterborough, sir.”

“Where!” cried Mr Limpney in astonishment.

“Peterborough, sir.”

“Now, will you have the goodness to tell me how you found out that?”

“On the map, sir.”

“Bless my soul!” exclaimed the tutor. “Well, go on. At what time from starting!”

“About ten o’clock, sir.”